Note! Israeli buildings and homes are built differently than what you
may be used to, and frequently they are poorly insulated. In the
winter time, when it is colder outside and warmer inside,
condensation can build up on windows and exterior walls. A humidifier
creates an even more moist environment.
EVERY DAY, air out your home by opening the windows. If it is super
cold outside, you can open the window one room at a time for 30 or
more minutes and avoid that room for the time being. This should
reduce the moisture and hopefully avoid any mold from growing.
You should also not put your furniture (especially upholstered
furniture) too close to an exterior wall as condensation can get on
the furniture item and, yep, you guessed it, mold can grow on it. One
of the only ways to kill mold is with bleach and as you know, bleach
isn't great for your furniture.
Stay warm, keep your throats moist, and be very vigilant about mold.